1. Field
The present disclosure relates to display devices.
2. Description of the Related Art
A portable electronic device (such as a mobile phone, a navigation device, a digital camera, an electronic book, a portable game machine, or various kinds of terminals) uses a liquid crystal display (LCD) or an organic light emitting diode (OLED) display. A display device used in the portable electronic device has been developed to have a flexible form in order to improve portability of the display device.
A flexible display device may be achieved by manufacturing a flat type of display device (a flat display device) and then bending it. In this case, while the flat panel display is being bent, a substrate thereof may be cracked. When a small size of crack (small size crack) occurs in the substrate, it may not be well detected early and may not greatly affect operation of the display device. The small size of crack may increase as time goes on, thus moisture may be permeated inside the display device through a portion where the crack occurs. When the moisture is permeated inside the display device, reliability thereof may decrease to affect operation of the display device.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the described technology and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.